Nickel removal agent and preparation method thereof

Abstract

The present invention discloses a nickel remover and its preparation method. The nickel remover comprises, by weight, 1-3 parts of cellulose salt, 5-15 parts of alkaline regulator, 0.2-0.5 parts of preservative, and 80-85 parts of pure water. The method comprises adding a measured amount of pure water to a reactor, raising the reactor temperature to 50°C, slowly adding a measured amount of cellulose salt to dissolve it, and maintaining the reactor temperature at 50-60°C throughout the dissolution process; stirring for 10 hours, and when the viscosity reaches ≥500 mPa·s, stopping stirring and allowing the solution to stand; adding the dissolved solution back to the stirred tank, stirring, and sequentially adding the alkaline regulator, preservative, and other raw materials according to the formulation requirements, dissolving and stirring until uniform, thereby completing the preparation of the agent. The remover can effectively remove nickel ions from wastewater, has a fast sedimentation rate, and the sediment is easily degraded naturally, greatly reducing secondary pollution to the environment. The product has a low cost and good economic value.

Description

Technical Field

[0001] The invention relates to the field of sewage treatment, discloses a new polymer material, and particularly relates to a nickel removal agent and a preparation method thereof. Background Art

[0002] The stainless steel refining process requires the addition of trace elements such as nickel, which are introduced into the production water during the steelmaking process. With the continuous improvement of national environmental protection requirements, the discharge of large amounts of nickel ions into water bodies will cause significant environmental damage. Therefore, the removal of nickel ions from production wastewater is a technical challenge that steel mills must address. Currently, there is a lot of research on this topic in China, but most products are expensive and have complex and demanding operating conditions, which poses a great challenge to the treatment of nickel-containing wastewater. Currently, conventional methods for treating nickel wastewater include precipitation, extraction, redox, adsorption, ion exchange, and biochemical methods. Precipitation, with its advantages of simple operation and low treatment costs, is the method adopted by most companies.

[0003] The chelation precipitation method involves adding compounds that react with nickel ions to wastewater to form insoluble salts. Organic and / or inorganic flocculants are then added to form flocculent precipitates, thereby capturing and removing nickel ions. Currently, disulfide and sulfur-nitrogen chelating agents are widely used. These compounds are easily oxidized in air, reducing their effectiveness and exhibiting poor stability. The compounds themselves contain elements such as sulfur and nitrogen, which can lead to secondary pollution during subsequent sludge treatment. Furthermore, the synthesis process is complex, resulting in high product costs.

[0004] The key to solving this problem is to urgently find a nickel wastewater treatment agent that is stable in quality, low in price and easy to use. Summary of the Invention

[0005] The purpose of the present invention is to provide a nickel remover and a preparation method thereof, which mainly solves the technical problems existing in the above-mentioned prior art. The remover has stable performance; does not contain sulfur and nitrogen elements, and the sludge is easily naturally degraded; has a fast sedimentation rate; and has a low product cost and good economic value.

[0006] The present invention discloses a technical solution:

[0007] A nickel remover for wastewater comprises the following components in parts by weight: 1-3 parts of cellulose salt, 5-15 parts of alkaline regulator, 0.2-0.5 parts of preservative and 80-85 parts of pure water.

[0008] Preferably, the cellulose salt is one or more of carboxymethyl cellulose sodium salt and hydroxyethyl cellulose sodium salt with a degree of substitution of 0.8 to 1.0 and a viscosity of 300 to 800.

[0009] Preferably, the alkaline regulator is one or more of sodium hydroxide and soda ash.

[0010] Preferably, the preservative is one or more of borax and isothiazolinone.

[0011] The present invention also discloses a method for preparing a wastewater nickel removal agent, which is as follows:

[0012] 1) Add a measured amount of pure water to the reactor, start stirring, start the reactor heating system, raise the reactor temperature to 50°C, slowly sprinkle in the measured cellulose salt to dissolve, and maintain the reactor temperature at 50°C to 60°C during the entire dissolution process; after stirring for 10 hours, take a sample and observe that the solution is a colorless, transparent, colloidal liquid with no particulate matter in the liquid, and measure the viscosity. When the viscosity is ≥500mPa·s, stop stirring and let it stand. After 24 hours, filter and set aside;

[0013] 2) Add the dissolved solution back into the stirring tank and start stirring. According to the requirements of the formula, add the alkaline regulator, preservative and other raw materials in sequence, dissolve and stir evenly, take a sample and observe the appearance of the sample. It is transparent and free of particles. The pH value is ≥9.5 and the density is ≥1.15, which is qualified. The preparation of the agent is completed.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. This nickel ion remover is environmentally friendly in the following three aspects. The remover of the present invention uses cellulose salt as its main component. Cellulose salt is a water-soluble polymer material mainly composed of three elements: carbon, hydrogen, and oxygen. Its decomposition products are non-toxic and harmless. Compared with traditional similar products, the nickel ion remover of the present invention does not contain sulfur or nitrogen elements. During subsequent sludge treatment, it will not emit harmful gases such as hydrogen sulfide and nitrogen oxides, which would cause secondary pollution. The product does not require the addition of flocculants such as PAC or PAM to aid flocculation during use, reducing the emission of flocculant components.

[0016] 2. The remover has good natural degradation ability, which can reduce the difficulty and cost of sludge treatment and is conducive to nickel recovery.

[0017] The present invention uses cellulose salt as the main component. Cellulose salt is easily degraded into small molecules of harmless substances under the influence of various factors such as cellulase, mold, and high temperature at room temperature. According to experimental data, the viscosity of cellulose salt in the natural environment decreases by about 40% in 14 days and about 90% in 28 days. The solution also appears green and has a foul odor, indicating that cellulose salt is easily degraded. As the agent diffuses, reacts, and settles in water, and is affected by other factors in the water, the degradation of the sedimentation products is more likely to occur. The bactericidal and antibacterial agent added to the present invention is mainly to ensure that the active ingredients of the product are not decomposed by fungi before use, so as to ensure the stable performance of the agent during production, transportation, and storage. If the bactericide is not added, the product has a shelf life of only one month, which indirectly proves the easy degradation of the product.

[0018] 3. The remover has a wide range of applications, fast nickel removal speed, high efficiency, simple production process, low price, easy promotion, and high cost performance.

[0019] When conventional disulfur and sulfur-nitrogen nickel removers are used to remove nickel from wastewater, the dosage concentration of the agent usually needs to be controlled at 200-300 mg / L. When auxiliary flocculants are added to accelerate sedimentation, the sedimentation reaction time must be more than 40 minutes. The technology of the present invention can effectively remove nickel ions in low-concentration nickel-containing wastewater by controlling the dosage concentration of the agent at 100-150 mg / L and reacting and settling for 25 minutes without adding other flocculants, thereby achieving the purpose of reducing operating costs. This can greatly shorten the wastewater treatment time and improve the system operation and treatment efficiency. The disulfur and sulfur-nitrogen nickel removers have complex production processes and high commodity prices. The nickel remover of the present invention can be obtained by compounding, has a simple production process, and has stronger economic benefits. The treated wastewater meets the total nickel emission limit requirements (total nickel ≤ 0.05 mg / L) in Table (3) of the "Water Pollutant Discharge Standard for the Iron and Steel Industry" (GB13456-2012). It is economical and reasonable, and provides technical support for the deep treatment of cold rolling wastewater and similar transformation projects in the steel industry. DETAILED DESCRIPTION

[0020] Example 1

[0021] An environmentally friendly nickel ion remover for wastewater. The ingredients are, by weight, 2 parts sodium carboxymethyl cellulose, 5 parts soda ash, 10 parts liquid caustic soda, 0.2 parts borax, and 82.8 parts pure water.

[0022] Preparation method of the nickel ion remover:

[0023] 1) Add a measured amount of pure water to the reactor, start stirring, start the reactor heating system, raise the reactor temperature to 50°C, slowly sprinkle in the measured amount of sodium carboxymethyl cellulose to dissolve, and maintain the reactor temperature at 50°C to 60°C during the entire dissolution process; after stirring for 10 hours, take a sample and observe that the solution is a colorless, transparent colloidal liquid with no particulate matter in the liquid, and measure the viscosity. When the viscosity is ≥500mPa·s, stop stirring and let it stand. After 24 hours, filter and set aside;

[0024] 2) Add the dissolved solution back into the stirring tank and start stirring. According to the requirements of the formula, add soda ash, borax, liquid alkali and other raw materials in sequence, dissolve and stir evenly, take samples and observe the appearance of the sample. It is transparent and free of particles. The pH value is ≥9.5 and the density is ≥1.15, which is qualified. The preparation of the agent is completed.

[0025] The wastewater from the special steel production of a large domestic steel enterprise was taken as a water sample, and the product of this embodiment was added at different concentrations. The data on nickel ion removal were measured as shown in Table 1:

[0026] Table 1: Nickel ion removal data of Example 1 product at different concentrations

[0027]

[0028]

[0029] As can be seen from the table above, the product of this embodiment already meets the emission limit standard at a dosage of 75 mg / L. For safety reasons, a dosage of 100 mg / L is generally recommended. Using the same water quality conditions and experimental methods, a commercially available nickel ion scavenger of a certain brand was added at a dosage of 200 mg / L. The nickel ion content was measured to be 0.041 mg / L, with a nickel ion removal rate of 92.68%. The product of this embodiment is significantly superior to commercially available products.

[0030] Table 2: Nickel ion removal data of the product in Example 1 under different pH conditions

[0031]

[0032] As shown in Table 2, the product of Example 1 can adapt to a wide pH range and has a good effect in the pH range of 6.0 to 10.0. Commercially available products generally require a use range of 8 to 9.5. Therefore, this product has a wider range of requirements for wastewater quality and the agent has a stronger ability to adapt to different water qualities.

[0033] Example 2

[0034] An environmentally friendly nickel ion remover for wastewater. The ingredients are 2 parts sodium hydroxyethyl cellulose, 5 parts soda ash, 10 parts liquid caustic soda, 0.3 parts isothiazolinone, and 82.7 parts pure water.

[0035] Preparation method of the nickel ion remover:

[0036] 1) Add a measured amount of pure water to the reactor, start stirring, start the reactor heating system, raise the reactor temperature to 50°C, slowly sprinkle in the measured amount of sodium hydroxyethyl cellulose to dissolve, and keep the reactor temperature at 50°C to 60°C during the entire dissolution process; after stirring for 10 hours, take a sample and observe that the solution is a colorless, transparent colloidal liquid with no particulate matter in the liquid, and measure the viscosity. When the viscosity is ≥500mPa·s, stop stirring and let it stand. After 24 hours, filter and set aside;

[0037] 2) Add the dissolved solution back into the stirring tank and start stirring. According to the requirements of the formula, add soda ash, isothiazolinone, liquid caustic soda and other raw materials in sequence, dissolve and stir evenly, take samples and observe the appearance of the sample. It is transparent and free of particles. The pH value is ≥9.5 and the density is ≥1.15, which is qualified. The preparation of the agent is completed.

[0038] The wastewater from the special steel production of a large domestic steel enterprise was taken as a water sample, and the product of this embodiment was added at different concentrations. The data on nickel ion removal were measured as shown in Table 3:

[0039] Table 3: Nickel ion removal data of Example 2 product at different concentrations

[0040]

[0041] As can be seen from the table above, the product of this embodiment meets the emission limit standard at a dosage of 75 mg / L. At a dosage of 100 mg / L or above, it fully meets the emission requirements. Throughout the static standing process, it is clear that the flocculated flocs are larger, and the flocculation process is faster than that of the sodium carboxymethyl cellulose product.

[0042] Table 4: Nickel ion removal data of the product in Example 2 under different pH conditions

[0043]

[0044] As can be seen from Table 4, the product of Example 2 has a good effect in the pH range of 6.0 to 10.0. As the pH value of the wastewater increases, the nickel ion removal capacity slowly increases.

[0045] Example 3

[0046] An environmentally friendly nickel ion remover for wastewater. The ingredients are, by weight, 1 part sodium carboxymethyl cellulose, 1 part hydroxyethyl cellulose, 5 parts soda ash, 10 parts liquid caustic soda, 0.2 parts isothiazolinone, and 82.8 parts pure water.

[0047] Preparation method of the nickel ion remover:

[0048] 1) Add a measured amount of pure water to the reactor, start stirring, start the reactor heating system, raise the reactor temperature to 50°C, slowly sprinkle in the measured sodium carboxymethyl cellulose and sodium hydroxyethyl cellulose to dissolve, and keep the reactor temperature at 50°C to 60°C during the entire dissolution process; after stirring for 10 hours, take a sample and observe that the solution is a colorless, transparent colloidal liquid with no particulate matter in the liquid, and measure the viscosity. When the viscosity is ≥500mPa·s, stop stirring and let it stand. After 24 hours, filter and set aside;

[0049] 2) Add the dissolved solution back into the stirring tank and start stirring. According to the requirements of the formula, add soda ash, isothiazolinone, liquid caustic soda and other raw materials in sequence, dissolve and stir evenly, take samples and observe the appearance of the sample. It is transparent and free of particles. The pH value is ≥9.5 and the density is ≥1.15, which is qualified. The preparation of the agent is completed.

[0050] The wastewater from the special steel production of a large domestic steel enterprise was taken as a water sample, and the product of this embodiment was added at different concentrations. The data on nickel ion removal were measured as shown in Table 5:

[0051] Table 5: Nickel ion removal data of Example 3 products at different concentrations

[0052]

[0053] As can be seen from the above table, the nickel removal effect is better when sodium carboxymethyl cellulose and sodium hydroxyethyl cellulose are used simultaneously.

[0054] Table 6: Nickel ion removal data of the product in Example 3 under different pH conditions

[0055]

[0056]

[0057] The product of Example 3 has a good effect in the pH range of 6.0 to 10.0. As the pH value of the wastewater increases, the nickel ion removal capacity slowly increases.

[0058] In addition, the nickel ion remover of the present invention can flexibly adjust the alkaline regulator component according to the water quality conditions at the customer's site, so that the wastewater is within the pH value range suitable for the agent to adapt to the acid and alkalinity requirements of different wastewaters, thereby achieving the best water treatment effect.

[0059] Description of the product's market application value: The use of the product of the present invention can significantly reduce water treatment costs compared to the commonly available dual-sulfur and sulfur-nitrogen nickel removers.

Claims

1. A nickel removal agent, characterized in that The composition comprises, by weight: 1 to 3 parts of cellulose salt, 5 to 15 parts of alkaline regulator, 0.2 to 0.5 parts of preservative, and 80 to 85 parts of pure water; The cellulose salt is one or more of carboxymethyl cellulose sodium salt and hydroxyethyl cellulose sodium salt with a degree of substitution of 0.8 to 1.0 and a viscosity of 300 to 800; The alkaline regulator is one or both of sodium hydroxide and soda ash; The preservative is one or more of borax and isothiazolinone.

2. The nickel remover according to claim 1, characterized in that The nickel removal agent is used under the condition of pH 6.0-10.

0.

3. A method for preparing the nickel removal agent according to claim 1, characterized in that: include: (1) Add a measured amount of pure water to the reactor, start stirring, start the reactor heating system, raise the reactor temperature to 50°C, slowly sprinkle in the measured cellulose salt to dissolve, and keep the reactor temperature at 50°C to 60°C during the entire dissolution process; after stirring for 10 hours, take a sample and observe that the solution is a colorless, transparent colloidal liquid with no particulate matter in the liquid, and measure the viscosity. When the viscosity is ≥500mPa·s, stop stirring and let it stand. After 24 hours, filter and set aside; (2) Add the dissolved solution back into the stirring tank and start stirring. According to the requirements of the formula, add the alkaline regulator and preservative raw materials in sequence, dissolve and stir evenly, take a sample and observe the appearance of the sample. If it is transparent and free of particles, the pH value is ≥9.5 and the density is ≥1.15, it is qualified. The preparation of the agent is completed.

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